Print the lines of file2 that are missing in file1

1 
 $ comm -23 file2 file1

Feb. 13, 2012, 8:26 a.m. — Anon9ge6A4uD

Explanation

The POSIX-standard comm utility can do this also.

  • -2 suppresses lines from the second argument (file1)
  • -3 suppresses lines appearing in both files

Limitations

Assumes that file1 and file2 are already sorted. If they are not, you can use process substitution to do so:

comm -23 <(sort file2) <(sort file1)

Process substitution is a bash-specific feature (also available in zsh but with a different syntax).

Related one-liners

0

Print the lines of file2 that are missing in file1 

 $ grep -vxFf file1 file2

Feb. 8, 2012, 2:42 p.m. — Janos

Explanation

  • -f is to specify a file with the list of patterns: file1
  • -F is to treat the patterns fixed strings, without using regular expressions
  • -x is to match exactly the whole line
  • -v is to select non-matching lines

The result is effectively the same as:

diff file1 file2 | grep '^>' | sed -e s/..//

Limitations

The flags of grep might work differently depending on the system. So yeah you might prefer the second way which should work everywhere. Nonetheless the various of flags of grep are interesting.